The more often a battery operated device, such as a wireless transmit/receive unit (WTRU), looks for possible data being sent to it, the more power the device consumes. In networks and devices that support not only telephony, but also data transmission, the manner in which the devices look for messages from the network varies, depending on whether the device is looking for incoming phone calls or incoming data transmissions.
With respect to telephony, users are accustomed to terrestrial networks wherein a ringing sound is heard almost immediately after a particular telephone number is dialed. To meet this expectation in wireless environments, a WTRU must frequently scan the network to minimize the delay in establishing a connection as perceived by a person placing a phone call. That is, the WTRU must frequently scan the network for incoming calls to minimize the time between when the network sends a calling signal or message and when the receiving WTRU actually checks for the calling signal.
This arrangement is quite suitable for telephony, but is inefficient for data transmission. With respect to data transmission, the strict requirements necessary for ensuring a near-instantaneous response to a call are not required. Longer delays are generally tolerated when transmitting data to WTRUs such as pagers and similar devices, for example. However, it is generally expected, that such devices respond to a message indicating that there is an incoming data transmission “in real time.” Therefore, the network must also be scanned rather frequently in some cases when dealing with data transmission, but even in such situations the frequency with which the network must be scanned is less then when dealing with telephony.
The amount of delay that is acceptable varies according to the type of data being transmitted and user preference. For example, longer delays are tolerated where information is infrequently updated, such as traffic or weather data. In the case of a pager, a reasonable response time could be evaluated in terms of an anticipated time delay for the user to respond to a paged message. In the case of multiple network transmissions (i.e. stock quotes, sport scores, etc.), some users want information occasionally updated so that they may have longer battery life. Other users have less concern for battery life and simply want data updated rapidly. Examples of users wishing frequent updates would be people desiring immediate information updates and people whose WTRU is connected to an external power supply. In the case of stock quotes, for example, there are casual watchers, and those who desire immediate notification of changes. Thus, if the user would expect to respond to a message quickly, the response time should ideally be fairly quick, but still much greater than the necessary response time for a WTRU becoming aware of an incoming telephone call.
It would therefore be desirable to have a method and system for efficiently supporting data transmissions as well as telephony.